Method of gaging temperatures of heated substances.



Patentd A r l, I902.

E. F. MORSE. I METHOD OF GAGING TEMPERATURES 0F HEATED SUBSTANCE S.

(Application filed Aug. 4, 1899.)

(Np Model.)

ByZW-J MW Adar/265 5 the true hrn'rns PATENT @nrrca EVERETT F. MORSE, OFTRUMANSBURG, NEW YORK.

METHOD OF GAGlNG TEMPERATURES OF HEATED SUBSTANCES.

$PEGIFICAEION forming part of Letters Patent No. 696,878, dated April 1,1902.

Application filed August 4,1899. Serial No. 726,101. o specimens.)

To all whom it may concern:

Be itknown that I, EVERETT FLEET Monsn, a citizen of the United States,and a resident of Trumansburg, in the county of Tompkins and State ofNew York, have invented certain newand useful Methods of GagingTemperatures of Heated Substances, of which the following is aspecification.

This invention relates to a novel method for gaging the temperature of aheating or heated substance which becomes luminous when heated.

The object of the invention is to provide for accurately determining thecritical degree of temperature to which it is necessary to heat steel,for example, in order to produce the best possible results in hardeningor in annealing it, and just as important as the above is its object 01:enabling a workman to reproduce in every succeeding piece of steel thesame result. This is of great importance in manufactories, where it isnecessary for economical and other reasons to produce in tools, parts ofmachines, and other devices uniformity in hardness, malleability, orduetility.

Methods heretofore employed for determining the temperature of heatedmetals for hardening or annealing have failed in producing uniformity inthe things treated and in arriving even infrequently at the bestresults.

In optical pyrometry the methods heretofore employed have consisted incomparing the substance to be tested with an optical standard arrangedat one side of the field of vision of said standard. With this methodtheobserver has to carry mentally from one to the other the color effectof either the substance or standard. The accuracy of the test depends onthe skill of the observer, and even with the best skill the effortnecessarily exerted to make accurate comparisons by this method is veryfatiguing, so much so that time for the eye to rest must be providedbetween observations. If in addition to thus carrying mentally the colorsensation of the standard or substance from one to the other andcomparing them the observer has to compensate or make allowance fordifferent optical sensations due to a substantial difference in the sizeor (to some extent) the shape of the standard and substance, then theaccuracy andreliability of'the comparisons are greatly impaired.

The above objects have been attained and the above difficulties havebeen overcome by my method of comparison, which is based on the factthat if two substances are made to produce in the eye the same coloreffects or sensations and one of them or a portion thereof is arrangedin the path of the rays passing from the other to the eye the portion ofthe one so arranged or superposed will merge in the other and apparentlybe obliterated from view.

The material selected for the standard may be of different compositionfrom the thing to be tested; but it must produce substantially the samesensation in the eye with respect to color. The merging effect abovereferred to is a well-defined phenomenon and enables the observer toeasily and at once detect when the substance is at the desiredtemperature, for were the temperature either above or below thetemperature indicated by the standard both would be visible, and thedifference in color would be sharply defined by the one appearingagainst the other, for the portion superposed would appear to be a partof the substance which lies beyond it and a part of whose rays itintercepts.

While the advantages of my method are greater when the standard andsubstance to be tested differ much either in shape or size, theadvantage is still great no matter what the standard may be.

If the material is brought to the exact temperature indicated by thestandard, the one will be completely merged into the other, and then thetemperature is gaged to the highest degree of accuracy of which mymethod is capable and to a degree of accuracy that is often greater thanis required in commercial work. However, my method is almost equallyadvantageous in gaging approximate temperatures, for if there isadifference in the temperature from that indicated by the standard thenthe one appears more or less plainly as a bright or dark portion on theother and one is partially merged in the other. In this case with thesuperposed method the difference in the temperature of the material fromthat indicated by the standard is then estimated, not by comparing thecolors principally, but

rather by the degree of distinctness with which the operator is able tosee the one superposed. This is very different from the method inside-by-side comparison, where the colors have actually to be compared,while with superposition it is principally only the difference inbrightness that is observed.

The method then consists in placing the standard in the path of the raysof light passing to the eye from the thing to be tested or in placingthe thing to be tested or a portion thereof in the path of rays of lightpassing to the eye from the standard, so that the outline of one or aportion thereof shall appear to overlap in whole or in part the field ofthe other, then bringing the heating. substance to a degree ofincandescence such that the outline of one or a superposed portionthereof will merge in the other to such a degree as to indicate thecorrect temperature within the necessary limits, or, if the most exactgaging of temperature is required, then by bringing the heated substanceto a degree of incandescence such that the outline of the one or thesuperposed portion thereof will disappear or become completely merged inthe other.

By a standard of substantially the same nature in respect toincandesence as the thing being tested is meant one that when heated tothe proper temperature produces upon the eye substantially the samecolor effects as said heated substance. Such standards may consistofmetal wires, carbon filaments, or the like, and are preferably heated toincandescence by means of an electric current flowing through them.

By this invention it is possible for a person of ordinary ability toproduce the same desired hardness, malleability, or ductility in everylike article, because by it he ean'accurately determine when eacharticle reaches the critical degree of temperature at which the bestresults can be produced.

It may be observed that it is not always practicable to vary thetemperature of the particular piece being gaged, as is often the case ingaging bars passing through rolls. If in this case the temperature of abar is either too high or too low, then the furnace may be adjusted soas to correct the temperature of the subsequentbars, the observationenabling the workmen to do this intelligently.

This application treats of the method of gaging temperature. The claimsupon the apparatus involved in its use form the subjectmatter of acompanion application filed November 9, 1899, under Serial No. 736,368.

This invention, therefore, further consists in the method herein fullyset forth and specified in the claims.

In the accompanying drawings, which form a part of this specification,Figure 1 represents the apparatus for carrying out the invention, andFig. 2 is another View of the lamp used therein.

The invention may be made effective by means of various apparatus.Thatillustrated Y has been found to work perfectly and will serve wellthe purpose of disclosing the invention. It consists of a tube 3, openat both ends, so that it may be looked througl1,though both or eitherend may be closed by any transparent substance,if desired. There islocated in the tube in any suitable manner a filament, as 4, which ismost conveniently inclosed in a vacuous bulb and constitutes anincandescent lamp. This filament may be of any suitable substance, butis preferably of carbon or platinum, and larger in cross-section thanthat of the ordinary incandescent lamp. It is also preferably coiled orlooped and is included in an electric circuit 5, supplied from a sourceof current, (indicated at 6,) which is preferably a storage battery,though it may be of any other sort. There is a suitable rheostat in thecircuit, as at '7, and a meter or indicator, as at 8, provided with itsusual scale. .A marker may be employed in the indicator, as representedat 9. This may be set at a predetermined point on the scale at which theindex must stand when the apparatus is used for gaging the temperatureof a certain batchor class of things to be hardened or annealed. Anumber of these markers may be employed when the apparatus is to be usedon various classes of work requiring heating to different temperatures.

The apparatus may be used as follows: By trial may be found theparticular degree of incandescence at which the requisite temper-- atureof the metal is reached. This is observed at the time and the rheostatmanipulated to produce the same degree of incandescence in the filamentt and the marker 9 set or the position of the indicator otherwise noted.The next article to be hardened or annealed may be viewed through thetube 3,

and when the temperature reaches the proper degree the degree ofincandescence of the article will be the same as that of the filament,and the latter, or at least that portion thereof on which the eye isfixed, will be obliterated or merged in the field of the heated metal.This condition is accurately and decisively determined, because thefilament will show light against the heating metalbefore it reaches thecritical temperature and dark against it should the temperature of themetal pass the critical point. In transit from one of these conditionsto the other there is a time when the filament or that portion thereofon which the eye is fixed is lost to view. That is the critical moment,and at that instantthe metal should be immersed in the hardening-bath orotherwise cooled, as the case may be. Attention is called to the factthat changes in degree of incandescence of a substance produce changesin the shade of color, and the term incandescence is used in the claimsin this sense. In addition to the employment of this means for producinguniformity in hardening and annealing it serves as a gage in'arriving atthe temper- IIO ature which is best suited to produce the desired effectin hardening or annealing any particular thing. If on trial it is foundthat a certain temperature is not quite high enough, a small amountofresistance may be cut out of the circuit 5, thereby slightly increasingthe brilliancy of the filament. The position of the indicator is thennoted, and the thingheating is brought to that temperature which willmake its degree of incandes cence identical with that of the filament.In this way repeated trials may be conducted with accuracy and the bestresult attained with certainty and despatch. Then when the best resulthas been attained the same degree of heat may thereafter be reproducedin any number of successive articles or things in which changes indegree of incandescence can be produced by changes in temperature.

The different degrees of incandescence include a range from the faintestoriginal luminosity due to heat to an iucandescence of the brightest orwhitest light.

By using with an electric current of constant voltage a carefully andminutely graded and graduated rheostat, the indicator, an ammeter orvoltmeter, may be dispensed with. and the position of the rheostat notedfor the.

various degrees of incandescence in the filament.

Obviously the electrical indicator is made to read in amperes or volts;but it may be calibrated to give readings in degrees of temperature, ifdesired, and the same device may be made to serve as the standard forvarious materials or substances. be then set for a particular degree oftemperature, and the substance or material to be treated may be broughtto that degree of incandescence which corresponds to that of thestandard when so set. Then the temperature of the material will be thesame as that for which the standard was set. From this it is obviousthat the standard, with its indicator, may also be used to read thetemperature of a luminous object.

Other means than the filament shown may be employed as a standard ofcomparison, and such standard maybe mounted in a different manner fromthat illustrated, and the luminosity of the standard may be effected byother means than by electricity without departing from the invention.Said standard may be any object or material whose appearance is such asto cause it or a portion thereof to merge into the field of saidsubstance when the desired degree of temperature therein is reached; noris this invention limited in its application to steel or other metals.It is applicable to any and all substances which become luminous whenheated.

Obviously more than one testing-tube, with its lamp, may be placed inthe same circuit to serve for several different operations. In that casethe lamps are preferably placed in parallel and every lamp brought tothe color of the dullest one by using with each of the The standard mayvbrighter ones sufficient resistance to effect that purpose.

I claim as my invention 1. The method of gaging the temperature of amaterial which becomes incandescent when heated, consisting in comparingsaid material heated to a luminous state with an optical standard, saidcomparison being made by placingsaid material and standard so that atleast a portion of one is in the path of the rays passing from the otherto the eye, observing the standard and material and noting if the onemerges in the other to such a degree as to indicate the correcttemperature within the necessary limits.

2., The'method of gagin g the temperature of a material which becomesincandescent when heated, consisting in comparing said material heatedto a luminous state with an optical standard, said comparison being madeby placing said material and standard so that at least a portion of oneis in the path of the rays passing from the other to theeye and varyingthe degree of heat until the color of one merges in that of the other.

The method of gaging the temperature of a material which becomesincandescent when heated, consistingin comparing said material heated toa luminous state with an optical standard, said comparisons being madebyplacing said material and standard so thatat least a portion of the-oneis in the path of the rays passing from the other to the eye, noting thedifference in color between the two Whereby it may be readily determinedwhether the temperature of the material is above or below that indicatedby the standard, and increasing or decreasing the heat of the materialuntil the one merges intothe other whereby it can easily and at once, bedetected when the material is atthe desired temperature.

4. The method of gaging the temperature of a material which becomesincandescent when heated, consisting in comparing said material heatedto a luminous state, with standard placed in the path of the rayspassing to the eye from said material so that a portionthereof issuperposed upon the field of said material, and varying the temperatureof the material so that that portion of the standard superposed maybemade to merge into the field of said material, thereby showing thatthedesired temperature thereof has been reached.

5. The method of gaging the temperatureof a substance when heated toincandescence,

consisting in comparing the degree of incandescence of said substancewith. a standard which is incandescent simultaneously therewith andincandescent to a degree corresponding to the incandescence of saidsubstance when heated to the desired temperature, said standard beinglocated in the path of therays passing from the heated substance to theeye.

(3. The method of gaging the temperature of a material consisting incomparing it with an optical standard whose color and luminositycorrespond to that resulting from a known degree of incandescence ortemperature, said comparison being made by placing one of them in therays passing to the eye from the other so that a portion at least of oneWill be superposed upon the field of the other, varying the temperatureof the material whereby it may be made to agree in color and luminositywith that of the standard and the portion of the one superposed made tomerge in the field of the other.

7. The method of determining the temperature of an incandescentsubstance consisting in placing in the path of the rays passing fromTompkins and State of New York, this 2d day 20 of August, A. D. 1899.

EVERETT F. MORSE.

Witnesses:

FRANK L. MORSE, DAVID B. PERRY.

